Abstract: A method and system of cognitive communication for generating non-interfering transmission, includes conducting radio scene analysis to find grey spaces using external signal parameters for incoming signal analysis without having to decode incoming signals. The disclosed cognitive communications system combines the areas of communications, signal processing, pattern classification and machine learning to detect the signals in the given spectrum of interests, extracts their features, classifies the signals in types, learns the salient characteristics and patterns of the signal and predicts their future behaviors. In the process of signal analysis, a classifier is employed for classifying the signals. The designing of such a classifier is initially performed based on selection of features of a signal detected and by selecting a model of the classifier.

Abstract: In a method of cognitive communication a system for generating non-interfering transmission, includes conducting radio scene analysis to find grey space using external signal parameters for incoming signal analysis without having to decode incoming signals.

Abstract: In a method of cognitive communication for non-interfering transmission, wherein the improvement comprises the step of conducting radio scene analysis to find not just the spectrum holes or White spaces; but also to use the signal classification, machine learning and prediction information to learn more things about the existing signals and its underlying protocols, to find the Gray space, hence utilizing the signal space, consisting of space, time, frequency (spectrum), code and location more efficiently.

Abstract: In a method of cognitive communication for non-interfering transmission, wherein the improvement comprises the step of conducting radio scene analysis to find not just the spectrum holes or White spaces; but also to use the signal classification, machine learning and prediction information to learn more things about the existing signals and its underlying protocols, to find the Gray space, hence utilizing the signal space, consisting of space, time, frequency (spectrum), code and location more efficiently. In a method of cognitive jamming where smart and energy efficient jamming techniques are suggested based on sensing, classification and machine learning of the existing signals.

Abstract: Interference cancellation techniques for use in a wireless multicarrier communications system where signals from multiple wireless networks might be present and interfering with the detection and demodulation processes are disclosed. Interference cancellation is applied to the interfering network before removing same-system interference. By removing the contribution of all interfering systems' from a receiver's aggregate signal, the receiver is capable of detection and demodulation. Performance can be further improved by including an additional level of interference cancellation within the system of interest to separate the individual user of interest.

Abstract: Techniques for multiple access differential M-ary coding applications that can be optionally aided by multiuser detection (MUD) are disclosed. An initial hopped feature decoding is performed to provide data estimates for each user represented in a received co-channel signal. Interference cancellation can then be performed using MUD, thereby providing an interference-cancelled signal. Data estimates remaining are then re-decoded. Iteration on the interference cancellation and re-decoding can be carried out to satisfy a particular rule of iteration, although iteration is not always necessary. The final decoded signal can then be provided to its destination.

Abstract: A system is presented that provides real-time performance for iterative multi-user detectors, such as Turbo MUDs, which are used to separate simultaneous transmissions on the same frequency, by permitting the MUD to use a less computationally intense, fast-processing algorithm and to correct for errors caused by the fast processing. In order to reduce the errors, a voting system is coupled to the output of the multi-user detector within the iterative system. The voting system provides confidence values on a bit-by-bit basis for the estimates made by the multi-user detector, with the confidence values then being utilized as soft inputs to a bank of conventional single-user decoders.

Abstract: An error correction decoding (ECC) processing scheme is disclosed that reduces computational complexity normally associated with multiuser detection (e.g., TurboMUD) solutions, without causing degradation in quality of service or decreasing the total throughput. Error correction decoding algorithms are applied only to portions of the estimates that were affected by the immediately previous MUD update process. Even though the MUD and/or ECC updating is targeted so as to reduce complexity of each iteration, all of the estimates are maintained and remain candidates for future updates. As such, there is no negative impact real-time or future performance. This targeting approach can be used in conjunction with many variations of MUD, including full-complexity or reduced complexity, and may include MUD with confidence ordering or voting, and other techniques for facilitating efficient and effective MUD processing.

Abstract: Techniques for multiple access differential frequency-hopped spread spectrum (MA-DFHSS) aided by multiuser detection (MUD) are disclosed. An initial DFH decoding is performed to provide data estimates for each user represented in a received co-channel signal. Interference cancellation is then performed using MUD, thereby providing an interference-cancelled signal. Data estimates remaining are then re-decoded. Iteration on the interference cancellation and re-decoding can be carried out to satisfy a particular rule of iteration, although iteration is not always necessary. The final decoded signal can then be provided to its destination.

Abstract: A multi-user turbo decoder combining multi-user detection and forward error correction decoding is disclosed in which randomly ordered indices are assigned to interfering users before a decoding tree is constructed in the multi-user decoder for each symbol interval for every iteration and for each new block of data. By building the decoding tree in this manner for each symbol interval, a reduced complexity search is more likely to include paths (and nodes) in the tree containing the correct value for the channel symbols. All users thus share in the benefit of root level placement in the decoding tree. In an alternative embodiment of the invention only one decoding pass is accomplished and there is no re-construction of the decoding tree based on further random index ordering for iterative decoding. No modification to the transmitted signaling method is needed.

Abstract: A reduced complexity Turbo multi-user detector (MUD) processing system in multiple access communications channels that decreases the likelihood of improper decoding of the final values of interest and decreases the computation complexity for each iteration, thereby allowing for a reduction in the number of iterations performed and lowers the overall complexity without negatively impacting performance. In one form the present invention comprises a multi-user detector coupled to two or more decoder sections, two ore more recoders, and a compare and adjust section in such a manner that data flows iteratively to correct for errors in a computationally efficient manner.

Abstract: A method and system begin at a random node of a trellis model having a set of at least two axes, wherein one axis corresponds to time and a second axis corresponds to frequency, a set of M states, corresponding to a set of all possible frequencies that may be transmitted by the system, and branches leaving each state, that terminate at allowable transmit frequencies for a next frequency hop. The number of branches leaving each state is dependent on the number of encoded bits per hop. Next, B bits of data are passed to a buffer, where B is the number of bits that will be transmitted per frequency hop. The method and system then combine the B bits of data with information for previously selected frequencies to select a current frequency, transmit the selected frequency, and feedback the currently selected frequency information to be used as previously selected frequency information when selecting a next frequency.

Abstract: A multi-user turbo decoder combining multi-user detection and forward error correction decoding is disclosed that utilizes iterative decoding of received, interfering signals, and the construction of a decoding tree of the decoder is changed for each iteration of the decoding based on the previous conditional probability estimates of the value of the data bits of each signal making up the received, interfering signals. Before each iteration of multi-user decoding, a probability estimate is calculated that the value of the bit in a signal has a certain value for all of the data bits. Using the probability estimate a new decoding tree is constructed before each iteration of decoding such that the signal bit having the most reliable estimate is assigned to the lowest or root level of the tree.

Abstract: A system is presented that provides real-time performance for iterative multi-user detectors, such as Turbo MUDs, which are used to separate simultaneous transmissions on the same frequency, by permitting the MUD to use a less computationally intense, fast-processing algorithm and to correct for errors caused by the fast processing. In order to reduce the errors, a voting system is coupled to the output of the multi-user detector within the iterative system. The voting system provides confidence values on a bit-by-bit basis for the estimates made by the multi-user detector, with the confidence values then being utilized as soft inputs to a bank of conventional single-user decoders.

Abstract: A Turbo multi-user detector (MUD) processing system in multiple access communications channels that decreases the likelihood of improper decoding of the final values of interest, thereby allowing for a reduction in the number of iterations performed and lowers complexity without negatively impacting performance. The present invention comprises a multi-user detector serially concatenated to two decoder sections in such a manner that data flows iteratively from the MUD and to each detector stage and back to the MUD to correct for errors.

Abstract: Interference cancellation techniques for use in a wireless multicarrier communications system where signals from multiple wireless networks might be present and interfering with the detection and demodulation processes are disclosed. Interference cancellation is applied to the interfering network before removing same-system interference. By removing the contribution of all interfering systems' from a receiver's aggregate signal, the receiver is capable of detection and demodulation. Performance can be further improved by including an additional level of interference cancellation within the system of interest to separate the individual user of interest.

Abstract: An error correction decoding (ECC) processing scheme is disclosed that reduces computational complexity normally associated with multiuser detection (e.g., TurboMUD) solutions, without causing degradation in quality of service or decreasing the total throughput. Error correction decoding algorithms are applied only to portions of the estimates that were affected by the immediately previous MUD update process. Even though the MUD and/or ECC updating is targeted so as to reduce complexity of each iteration, all of the estimates are maintained and remain candidates for future updates. As such, there is no negative impact real-time or future performance. This targeting approach can be used in conjunction with many variations of MUD, including full-complexity or reduced complexity, and may include MUD with confidence ordering or voting, and other techniques for facilitating efficient and effective MUD processing.

Abstract: A method and system begin at a random node of a trellis model having a set of at least two axes, wherein one axis corresponds to time and a second axis corresponds to frequency, a set of M states, corresponding to a set of all possible frequencies that may be transmitted by the system, and branches leaving each state, that terminate at allowable transmit frequencies for a next frequency hop. The number of branches leaving each state is dependent on the number of encoded bits per hop. Next, B bits of data are passed to a buffer, where B is the number of bits that will be transmitted per frequency hop. The method and system then combine the B bits of data with information for previously selected frequencies to select a current frequency, transmit the selected frequency, and feedback the currently selected frequency information to be used as previously selected frequency information when selecting a next frequency.

Abstract: Techniques for multiple access differential M-ary coding applications that can be optionally aided by multiuser detection (MUD) are disclosed. An initial hopped feature decoding is performed to provide data estimates for each user represented in a received co-channel signal. Interference cancellation can then be performed using MUD, thereby providing an interference-cancelled signal. Data estimates remaining are then re-decoded. Iteration on the interference cancellation and re-decoding can be carried out to satisfy a particular rule of iteration, although iteration is not always necessary. The final decoded signal can then be provided to its destination.

Abstract: A real-time multi-user detection (MUD) receiver processing simultaneous digitally modulated interferers and transmissions in the same frequency optimizing performance for heavily loaded and overloaded multiple access systems by implementing an iterative TurboMUD receiver using tree-pruning, including confidence ordering, power-ordering, and a voting procedure. On the first iteration, user indices are ordered according to received powers. On subsequent iterations, the voting system provides soft decisions or confidence values utilized as soft inputs to single-user decoders. Voting is computationally attractive and allows the bank of decoders to operate on soft values, improving performance and reducing the number of turboMUD iterations. The bank of soft output error correction decoders produces an improved set of soft decisions or confidence values corresponding to the channel bits transmitted by each interfering user.